Getting System Information from Linux

Most of the information I gather for my Linux version of my uptime program comes from procfs.

/proc/sys/kernel/hostname

Provides me the one word hostname of this kernel. I’m planning on switching this and /proc/version to a uname() syscall (see man 3 uname) to provide better compatibility on systems without /proc.

/proc/uptime

Provides me the raw number of seconds (including factional) since the computer booted, as well as the total number of seconds this computer has been idle (the second bit I discard)

/proc/loadavg

Provides me with the three load averages

/proc/version

Provides me with a long kernel version, which is different than the one supplied by uname -a.

/proc/meminfo

I get all of my memory information from here, but I don’t use all of the information available to me. Most of it is pretty useless, but I do get:

• Total Memory
• Buffered Memory
• Cached Memory
• Free Memory
• Total Swap
• Free Swap

I get ‘memory used’ from the formula: “int memused = memtotal - cached - buffers - memfree;”